Kali Linux Help

I recently downloaded Kali Linux from Offensive Security and installed it into Virtual Box. I had specifically chosen the 64 bit version as I had assumed my Windows 7 OS with an Intel Core i3 was 64 bit, though upon configuring the General settings all the Linux operating systems listed came out as 32 bit, though I had checked earlier that I did indeed install the 64 bit version from the website.

It seemed to work fine at first, as I made it to the Boot Up menu of Kali and chose Install, however the process never works because the Boot menu keeps giving me a message stating:

This kernel requires an x86-64 CPU, but only detected an i686 CPU.

Unable to boot - please use kernel appropriate for your CPU.

Under System Settings of Virtual Box I noticed under the Processor tab that the CPU was locked at 1 and I had no access to the Acceleration tab. I tried looking through for a solution on Youtube, where some tutorials suggested PAE/NX might help, though in my case it didn't change the CPU error.

Could anyone here please help me with this issue, as I really wish to be able to use Kali.